Well, I started doing the 90 day routine on 16/09/2013 and because of being busy with studying and other stuff, I havent really followed it trough, with lots of interruptions between exercises including whole weeks without any exercise.
But, a bit more than two weeks ago I started doing the 2 day 1 off and now I'm doing the 5 days two off routine. I decided to measure it to see if despite my lack of commitment I had gained anything and to my surprise I did gain a bit of thickness, EG went from 12cm(4.72 inches) to 12,2cm(4.80 inches).

So, now I am doing the 5days/2off routine religiously and I got the definitive proof this method works. Also, erections are way better.